Download - Diving Medicine for SCUBA Divers

EXPLOSIONS –
UNDERWATER BLAST
This topic is included only as a warning
for recreational divers not to use
explosives underwater. Military divers are
particularly at risk from these hazards,
even in training – because of the use of
"scare charges" which are designed to
discourage underwater saboteurs and are
sometimes used in the vicinity of trainee
divers to toughen them up.
When an underwater explosion is
observed from the surface, a sudden
explosive projection of water and foam
into the air can be seen immediately after
the explosion. This is the effect of the
pressure wave emanating from the blast
when it meets an air–water interface.
A similar effect is produced at air–tissue
interfaces in the body as the shock wave
travels through the diver. This can shred
tissues such as lungs, intestines, sinus
Fig. 32.1
cavities and the middle ear spaces, which
are in contact with air – all gas containing spaces within the body can be
affected.
Clinical features.
The organs worst affected are the lungs and intestines. Rupture and bleeding
of the tissues in the lungs and bowel cause:
• chest pain
• shortness of breath
• vomiting or coughing up of blood
• passage of bloody or black bowel motions.
Damage to the ears and sinuses causes features similar to barotrauma.
Ruptured ear drums and deafness are particularly common.
If a diver is caught in the water where an explosion is inevitable, some
protection can be afforded by attempting to float on his back, on the surface
– this will remove some of the air containing tissues from contact with the
water.
Chapter 32 — 12